By default ASP.net 2.0 uses garbage collection that is designed for a multi-processor environment. If your server does not have multiple CPUs or you are seeing excessive Out of Memory exceptions, disabling this garbage collection should bring memory usage down.

First open the aspnet.config file with a text editor like Notepad. This file can be found here:
.NET Framework 2.0:
%SystemRoot%\Microsoft.NET\Framework\v2.0.50727\Aspnet.config